Provided is a catheter of which the inner diameter is significant relevant to the outer diameter and in which crossabilty of a medical instrument with respect to a lumen of te catheter can be favorably ensured even in a case where a kink occurs.A catheter (1) includes an inner layer (22) that forms the inner surface of a tubular catheter main body (2) having a lumen (21)；an outer layer (23) that forms the outer surface of the catheter main body (2)； and multiple reinforcements (25) that are embedded between the inner surface and the outer surface.When the catheter main body (2) is bent 180° and a kinked portion is made, the lumen (21) of the catheter main body (2) at the kinked portion at the time an angle is formed by the kinked portion returns to 90° and allows a guide wire having an outer diameter of 0.89 mm to be inserted therethrough.
